Maybe you think getting cancer is kind of a tossup, or that it's something left to the genetic gods that you have no control over. But the truth is, you do have control, every time you put something in your mouth. Turns out, lifestyle factors are involved in most cancers—factors you control are estimated to account for 90 percent of all causes of cancer, and of that, diet may account for 35 percent.

Food really is the best preventive medicine. We see this in real life when we look at the cultures that live the longest, aka the blue zones. Though they’re scattered around the world—from Okinawa, Japan, to Ikaria, Greece, to Sardinia, Italy—they all have one thing in common: good food. Generally, in these communities, where it's not uncommon to live to be 100, people eat loads of whole fruits and vegetables, plenty of fish and olive oil, beans, whole grains, minimal red meat, and maybe drink some red wine in moderation.

But it's not the locations themselves that are special. Consider the Mediterranean diet, which anyone can adopt, and how it's associated with a reduced risk of all sorts of cancers, including breast and colon cancer.

Foods can fight cancer both indirectly and directly. Indirectly, selecting the right combination of foods (i.e., whole, minimally processed, fruit- and veggie- heavy, high in fiber) will keep you at a healthy body weight, which reduces your risk of most cancers. And directly, many studies reveal that individual phytochemicals (natural plant chemicals), vitamins, and minerals demonstrate promising cancer-fighting properties.

"Research shows that after just three months on an intensive lifestyle program including a whole-foods plant-based diet, over 500 genes that regulate cancer are beneficially affected, either turning off cancer-causing genes or turning on the cancer-protective genes," Mark Hyman, M.D., functional medicine doctor and New York Times best-selling author, told mbg.

The synergy of compounds in someone's overall diet is what experts believe offers the strongest protection—which is why an emphasis is placed on consuming them from potent food sources rather than supplements.

The idea is, if you load up on these cancer-fighting foods, you'll tip the scale in your favor.

What makes something a cancer-fighting food?

Many of the foods you're about to learn about contain a variety of phytochemicals, vitamins, and minerals that help prevent or fight cancer in different ways. For instance, phytochemicals (polyphenols, flavonoids, etc.) are compounds that plant foods produce to protect themselves against environmental threats like predator insects, pollution, and disease—and these properties may be why they're helpful in warding off human diseases, too. Here are several of the mechanisms by which these nutrients may help prevent cancer or halt its growth in humans:

Contains antioxidant properties:

A variety of vitamins and phytochemicals have antioxidant properties, including vitamin C, vitamin E, carotenoids (like lycopene, lutein, and beta-carotene). The body is constantly using these antioxidant compounds to help protect our tissues and DNA from damage that happens as a result of either normal cell metabolism or exposure to things like pollution, chemicals, cigarette smoke, and sun exposure. Because this damage is linked with increased cancer risk, many antioxidants may help protect against cancer.

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Reduces inflammation:

"Inflammation is the common thread connecting most chronic diseases, including cancer," says Hyman. Acute inflammation in response to an injury is healthy. But chronic inflammation caused by obesity, infections that don't go away, or abnormal immune reactions can cause DNA damage that leads to cancer. For example, people with chronic inflammatory bowel diseases, such as ulcerative colitis, have an increased risk of colon cancer. Many foods have anti-inflammatory properties that could change this process.

Interferes with angiogenesis:

Angiogenesis is the process of creating new blood cells. While it's essential for things like healing wounds, abnormal or uncontrolled angiogenesis can promote the growth and spread of cancer since tumors require new blood vessels to grow and expand. But some foods (often antioxidant-rich fruits and veggies) have potent anti-angiogenic properties that help keep this process in check, interfering with the ability of cancer cells to grow these new blood vessels and metastasize or spread to other parts of the body.

Promotes apoptosis:

When cells in our bodies recognize viruses or gene mutations, or become damaged or aged, they may induce their own death to prevent the damage from spreading. This process is called apoptosis, and it's vital to proper immune system functioning. But with cancer, malignant cells have learned how to avoid apoptosis, allowing them to spread. Some nutrients in food, however, seem to give our immune system a hand in eliminating these cancerous cells, which helps prevent the growth and metastasis of the cancer.

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Not a one-size-fits-all approach:

Of course, all cancers behave somewhat differently in the body, and thus, they respond to certain foods and nutrients differently. This means that some foods that help prevent lung cancer may not prevent breast cancer, and vice versa. Along the same lines, foods that promote one type of cancer won't necessarily promote another type.

Here, learn general tips on how you should be eating to avoid two of the most common types of cancer—lung cancer and breast cancer—plus specific cancer-fighting foods that may offer additional protection:

Breast-cancer-fighting foods and diet

Breast cancer is the most common cancer among women, with about 266,120 new cases of invasive breast cancer diagnosed every year. You can curb your risk, though. Some studies find that a diet rich in vegetables, fruit, fish, and low-fat dairy products has been associated with a lower risk of breast cancer. In general, fat doesn't appear to have a negative impact on breast cancer, so seeking out only foods low in fat isn't recommended (just think about all those omega-3s you'd be missing!).

Reducing your alcohol intake is also strongly advised—one study found that having just one alcoholic drink per day increased a woman's risk of breast cancer by 1.2 times compared to women who never drank. Experts believe that alcohol increases levels of hormones associated with hormone-receptor-positive breast cancer, including estrogen. Some experts also advise reducing your exposure to xenoestrogens, synthetic compounds that have estrogen-like activity. Pesticide residue on produce and hormone residues in meat and dairy may be a source of xenoestrogens in your diet, so choosing organic options when possible is a good strategy.

Here are some specific breast-cancer-fighting foods that may naturally lower your risk:

1.
Olive oil

Swap out processed, pro-inflammatory vegetable oil for extra-virgin olive oil. One large research review found that women who consumed the most olive oil in their diets had a lower risk of breast cancer as well as cancers of the digestive system (including colon cancer). One possible reason: a phenolic compound in olive oil called oleocanthal. This phytochemical, which gives olive oil its peppery bite, exhibits strong anti-inflammatory properties, slows cancer cell growth, and induces apoptosis on cancer cells in lab studies.

2.
Salmon

Opt for fatty fish. The omega-3 fats EPA and DHA, found in fatty fish like salmon and sardines, may inhibit the growth of breast cancer tumors. A research review revealed that women with a higher intake of these fats compared to certain omega-6 fats had a lower risk of breast cancer, due in part to a reduction in pro-inflammatory fat derivatives. These fish also contain vitamin D, which is associated with a lower risk of breast cancer.

3.
Broccoli sprouts

Sprinkle some sprouts on your next salad. Broccoli sprouts are part of the cruciferous veggie family (broccoli, cauliflower, Brussels sprouts, watercress, arugula, etc.) known for their potent cancer-fighting properties. They also give new meaning to "small but mighty." In one study, researchers compared the cancer-preventive benefits of sprouts with mature broccoli and found that they contained up to 50 times more glucoraphanin, a phytochemical and precursor to sulforaphane, that helps neutralize cancer-causing chemicals before they damage a cells' DNA.

4.
Mushrooms

Consider making your next batch of tacos with sautéed mushrooms instead of ground beef. In one study, women who ate the most fresh button mushrooms (⅛ cup or more per day) were about 66 percent less likely to develop breast cancer than non-mushroom eaters. This could be due to the fact that they contain natural aromatase inhibitors, which are substances that can block production of estrogen. Some experts say you're even better off opting for Asian varieties such as shiitake, maitake, or oyster mushrooms. And whatever you do, be sure to cook them. Raw mushrooms can actually contain substances called hydrazines that may promote cancer.

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5.
Green tea

It's time to get familiar with matcha. Green tea consumption—as little as one cup per day—has been associated with a reduced risk of cancer overall. This is probably due to green tea's most prominent polyphenol, epigallocatechin-3-gallate (EGCG), which has been shown in lab studies to upregulate genes that slow cancer growth and downregulate genes that spread breast cancer. Matcha tea may contain more EGCG than brewed tea since you're consuming the whole crushed leaf.

6.
Parsley

Sprinkle some parsley into your next salad. This herb, along with celery and chamomile tea, are some of the most potent sources of the polyphenol apigenin. In a promising lab study, apigenin was shown to induce apoptosis, meaning it stopped breast cancer cells from preventing their own death, which would have allowed them to proliferate and spread.

7.
Flaxseed

Add some fresh ground flaxseed to your next green smoothie or bowl of oatmeal. High-fiber foods, like flax, may help you maintain a healthy weight, which is key for reducing cancer risk. Flaxseeds also contain polyphenols called lignans. These compounds are considered phytoestrogens (or plant estrogens, a weak form of estrogen), and there was once concern that they may interfere with cancer medications, but this now doesn't seem to be the case. In fact, recent lab studies suggest that flaxseeds, lignans, and flax oil may help slow tumor growth and slow the spread of both estrogen-receptor-positive (ER+) and estrogen-receptor-negative (ER-) breast cancer.

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8.
Organic edamame

Make edamame your new go-to snack. As with flaxseeds, the isoflavones in soy have mild estrogenic properties, but these seem to be outweighed by the perks of this cancer-fighting food, and current research supports the consumption of up to three servings of whole soy foods per day as part of a healthy, cancer-fighting diet. In fact, a number of population-based studies have found soy to be beneficial. A review of 35 studies from Asian countries found that soy intake reduced breast cancer risk by 40 percent in both pre- and postmenopausal women. Just opt for organic soy when possible, as most conventional soy is genetically modified and may be contaminated with pesticides.

9.
Raspberries

Toss some berries into your next smoothie. Loaded with fiber and antioxidant phytochemicals, berries are a potent, natural cancer-fighting food. Research shows that a series of phytochemicals found in berries such as cyanidin, delphinidin, quercetin, kaempferol, ellagic acid, resveratrol, and pterostilbene interact and interfere with key pathways in breast cancer and induce apoptosis (programmed cell death) of cancer cells, thus lowering breast cancer risk. All berries, but particularly raspberries and strawberries, are rich in ellagic acid, which may be particularly beneficial.

10.
Kale and other leafy greens

Don't underestimate the power of a loaded mixed greens salad to fight cancer. Dark leafy greens like kale, spinach, arugula, mustard greens, and Swiss chard are packed with fiber, folate, and a variety of phytochemicals such as the carotenoids lutein and zeaxanthin. Carotenoids found in leafy greens have been shown to inhibit the growth of some breast, lung, skin, and stomach cancer cells in lab studies, while folate (from food, not supplements) has been associated with a reduced risk of several cancers.

11.
Turmeric

A number of spices may help reduce breast cancer risk, thanks to their concentration of phytochemicals and other bioactive compounds. But turmeric, with its high concentration of curcumin, may take the cake as the most potent cancer-fighting spice. Not only are people whose diets are rich in turmeric less likely to get breast cancer (as well as lung and colon cancers), but research shows that curcumin may help prevent breast cancer from metastasizing, or the spreading from the breasts to another area of the body. Curcumin has also been shown to boost the effectiveness of the common chemotherapy drug Taxol. Some experts believe that consuming turmeric, as opposed to curcumin supplements, is more beneficial due to the presence of additional compounds that may have synergistic properties. Here's how to make delicious, inflammation-fighting turmeric tea.

Lung-cancer-fighting foods and diet

Did you know that every year, more people die of lung cancer than of colon, breast, and prostate cancer combined? And it's not just smokers who are at risk. Accumulating evidence shows that diet may play a significant role in this disease. Diets high in fruits and vegetables may decrease risk, while consumption of red meat, saturated fats, and dairy products have been associated with greater risk.

Most recently, a study showed an increased risk of lung cancer in nonsmokers whose diet was high on the glycemic index (GI)—meaning, high in foods that raise blood sugar relatively quickly. Increased blood sugar, in turn, can increase insulin-like growth factors (IGFs), which have been associated with increased lung cancer risk. Foods high on the GI are generally low in fiber and include white potatoes, white rice, pasta, juice, and cereal. You should also avoid supplements (but not foods) containing beta-carotene, which might further increase your lung cancer risk.

Here are some specific lung-cancer-fighting foods that may naturally lower your risk:

1.
Apples

There's a reason the saying is: An apple a day, may just keep the doctor away. Apples, along with pears, contain the phytochemical phloretin, which may play a role fighting cancer and complementing chemotherapy drugs. In one lab study, phloretin effectively induced apoptosis (programmed cell death) in lung cancer cells, while another study found that it enhanced the anti-cancer effect of the commonly used chemotherapy drug cisplatin. Apples also pack a dose of fiber and another phytochemical called quercetin, which appears to have a role in inhibiting the growth of several cancers.

2.
Papaya

This tropical fruit—along with butternut squash, red bell peppers, oranges, and peaches—is a great source of the carotenoid beta-cryptoxanthin, which has been associated with a 25 percent reduced risk of lung cancer among nonsmokers who get the most of it in their diet. Just don't attempt to obtain this or other carotenoids from supplements—that could actually boost your cancer risk. Additionally, papaya contains loads of vitamin C and folate, both of which play a role in reducing cancer risk.

3.
Pistachios

These super-healthy nuts are a good source of vitamin E, which a large, population-based study found to be an important addition to the diet. Specifically, women who were exposed to smoke at work were 47 percent less likely to get lung cancer if they also ate a diet high in vitamin E (supplements of this vitamin, on the other hand, should be avoided as they can increase lung cancer risk). In addition to pistachios, good sources of vitamin E include sunflower seeds, almonds, and wheat germ. Pistachios also contain lutein and zeaxanthin, two carotenoids associated with a reduced risk of lung cancer.

4.
Arugula

Like broccoli and Brussels sprouts, arugula is a cruciferous veggie, all of which contain the potent cancer-fighting compound sulforaphane. Eating these vegetables has been strongly associated with a reduced risk of several cancers, particularly lung and colon cancer. Sulforaphane appears to work, in part, by inhibiting the enzyme histone deacetylase, which is known to be involved in the growth and spread of cancer cells. Additionally, arugula is a leafy green, delivering a range of nutrients that may fight cancer, including fiber, folate, carotenoids, and flavonoids.

5.
Oysters

Oysters make the perfect cancer-fighting appetizer. Along with other shellfish, they're a great source of zinc, which is important for overall immune functioning. Research shows that this mineral may help fight lung cancer by inducing apoptosis (programmed cell death) of lung cancer cells and boosting the effectiveness of the common chemotherapy drug docetaxel. Both zinc-containing foods and zinc supplements may help.

6.
Garlic

Here's a reason to embrace garlic breath: A population-based study found that people who consumed raw garlic at least twice a week reduced their risk of lung cancer by 44 percent. And yes, raw garlic seems to be key, since the garlic's allyl sulfur compounds are believed to be responsible for its benefits and they are greatly decreased when exposed to heat. These compounds may work, in part, by turning on cancer-suppressing genes in the body, inhibiting angiogenesis (blood vessel growth) and repairing DNA.

7.
Red onions

Red onions, along with capers and apples, are a top source of quercetin, a phytochemical with potent antioxidant properties that's been shown to inhibit the growth of several cancers. A recent animal study found that quercetin was effective at inhibiting the metastasis (the migration of cancer to another part of the body, and a top cause of death from cancer) of lung cancer as well as increasing the survival time of mice with lung cancer. Bonus: Heating onions doesn't seem to lower their quercetin content.

8.
Blueberries

These and other deeply hued fruits contain a family of anti-inflammatory flavonoids called anthocyanosides, which many experts believe are some of the most potent phytochemical antioxidants we've discovered. Blueberries are also one of the top food sources of the phytochemical pterostilbene, which has been shown to induce apoptosis (programmed cell death) of lung, stomach, pancreatic, and breast cancer cells. Pterostilbene may also be an effective anti-cancer agent based on its antineoplastic properties—the ability to prevent, inhibit, or halt the development of a tumor.

9.
Ginger

Both fresh and powdered ginger contain potent anti-inflammatory and anti-oxidative compounds (gingerols, shogaols, and paradols) that make it great for lowering risk for inflammation-related diseases like cancer. It also helps keep blood sugar and insulin levels balanced, which may indirectly reduce the risk of a variety of cancers by keeping insulin-like growth factors in check. Additionally, lab studies suggest that a compound in ginger called 6-shogaol may directly interfere with the pathways that normally help lung cancer cells spread, which reduces the likelihood of metastasis (the spread of cancer from one area of the body to another).

10.
Beans and lentils

Not only are beans and lentils a fantastic source of fiber, which may reduce cancer risk, but they're also loaded with folate, which is anti-inflammatory. This B vitamin may be of particular importance to people who smoke or who have recently quit since smoking lowers folate levels in the body. One population-based study even found that smokers who got more folate in their diets reduced their risk of lung cancer by 40 percent, suggesting that it helps protect healthy cells from carcinogens in tobacco smoke. Other great sources of folate include leafy greens and citrus.

Bottom line on eating to prevent cancer.

These widely available cancer-fighting foods contain nutrients and phytochemicals that have been shown to help fight or prevent the development of cancer. However, your overall diet matters way more than the consumption of a few individual foods from the above lists. A good first step to bolster your body's cancer-fighting potential: Start eliminating pro-inflammatory foods that are high in sugars and/or refined carbohydrates. Then start layering in the good stuff—whole, minimally processed foods with a variety of colorful fruits and veggies (aim for at least five servings of fruits and veggies daily) and as many of the picks above as possible. Variety is your friend!

Of course, don't simply use these cancer-fighting foods as a substitute for medical care. If you currently have cancer, ask your doctor if any particular foods might interfere with your treatment plan.